Often, when we’re presented with strong evidence that our belief is false, we can easily change our mind. Show me I’m mistaken in believing that the Matterhorn is near Chamonix, and I’ll just drop that belief.
However, abandoning a belief isn’t always so easy. That’s particularly the case for beliefs in which we have invested a great deal emotionally, socially and/or financially. When it comes to religious and political beliefs, for example, or beliefs about the character of our close relatives, we can find it extraordinarily difficult to change our minds. Psychologists refer to the discomfort we feel in such situations – when our beliefs or attitudes are in conflict – as cognitive dissonance.
Perhaps the most obvious strategy we can employ when a belief in which we have invested a great deal is threatened is to start explaining away the evidence.
Here’s an example. Dave believes dogs are spies from the planet Venus – that dogs are Venusian imposters on Earth sending secret reports back to Venus in preparation for their imminent invasion of our planet. Dave’s friends present him with a great deal of evidence that he’s mistaken. But, given a little ingenuity, Dave finds he can always explain away that evidence:
‘Dave, dogs can’t even speak – how can they communicate with Venus?’
‘They can speak, they just hide their linguistic ability from us.’
‘But Dave, dogs don’t have transmitters by which they could relay their messages to Venus – we’ve searched their baskets: nothing there!’
‘Their transmitters are hidden in their brain!’
‘But we’ve X-rayed this dog’s brain – no transmitter!’
‘The transmitters are made from organic material indistinguishable from ordinary brain stuff.’
‘But we can’t detect any signals coming from dogs’ heads.’
‘This is advanced alien technology – beyond our ability to detect it!’
‘Look Dave, Venus can’t support dog life – it’s incredibly hot and swathed in clouds of acid.’
‘The dogs live in deep underground bunkers to protect them. Why do you think they want to leave Venus?!’
You can see how this conversation might continue ad infinitum. No matter how much evidence is presented to Dave, it’s always possible for him to cook up another explanation. And so he can continue to insist his belief is logically consistent with the evidence.
But, of course, despite the possibility of his endlessly explaining away any and all counterevidence, Dave’s belief is absurd. It’s certainly not confirmed by the available evidence about dogs. In fact, it’s powerfully disconfirmed.
The moral is: showing that your theory can be made to ‘fit’ – be consistent with – the evidence is not the same thing as showing your theory is confirmed by the evidence. However, those who hold weird beliefs often muddle consistency and confirmation.
Take young-Earth creationists, for example. They believe in the literal truth of the Biblical account of creation: that the entire Universe is under 10,000 years old, with all species being created as described in the Book of Genesis.
Polls indicate that a third or more of US citizens believe that the Universe is less than 10,000 years old. Of course, there’s a mountain of evidence against the belief. However, its proponents are adept at explaining away that evidence.
Take the fossil record embedded in sedimentary layers revealing that today’s species evolved from earlier species over many millions of years. Many young-Earth creationists explain away this record as a result of the Biblical flood, which they suppose drowned and then buried living things in huge mud deposits. The particular ordering of the fossils is supposedly accounted for by different ecological zones being submerged one after the other, starting with simple marine life. Take a look at the Answers in Genesis website developed by the Bible literalist Ken Ham, and you’ll discover how a great deal of other evidence for evolution and a billions-of-years-old Universe is similarly explained away. Ham believes that, by explaining away the evidence against young-Earth creationism in this way, he can show that his theory ‘fits’ – and so is scientifically confirmed by – that evidence:
Increasing numbers of scientists are realising that when you take the Bible as your basis and build your models of science and history upon it, all the evidence from the living animals and plants, the fossils, and the cultures fits. This confirms that the Bible really is the Word of God and can be trusted totally.
[my italics]
According to Ham, young-Earth creationists and evolutionists do the same thing: they look for ways to make the evidence fit the theory to which they have already committed themselves:
Evolutionists have their own framework … into which they try to fit the data.
[my italics]
But, of course, scientists haven’t just found ways of showing how the theory of evolution can be made consistent with the evidence. As we saw above, that theory really is strongly confirmed by the evidence.
Any theory, no matter how absurd, can, with sufficient ingenuity be made to ‘fit’ the evidence: even Dave’s theory that dogs are Venusian spies. That’s not to say it’s reasonable or well confirmed.
Of course, it’s not always unreasonable to explain away evidence. Given overwhelming evidence that water boils at 100 degrees Celsius at 1 atmosphere, a single experiment that appeared to contradict that claim might reasonably be explained away as a result of some unidentified experimental error. But as we increasingly come to rely on explaining away evidence in order to try to convince ourselves of the reasonableness of our belief, we begin to drift into delusion.
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